Introduction: Gambling is a conscious and deliberate effort of betting money or something of value on an uncertain outcome with the primary intent of gaining advantage or benefit. This study was conducted to describe the categories gambling in an Iranian context. Methods: Using content analysis and saturation principles, gamblers were recruited and interviewed. Data were analyzed using constant comparison in open, axial, and selective coding stages. Results: Legal gambling (including betting on horse riding, swimming and shooting) and illegal gambling (including betting on animal racing or fighting, betting on games with cards, betting on sports, betting on games with diceor card, Ghap, and betting on car numbers) are two main categories of gambling in Iranian context. "Illegal and underground gambling in Iran and its Security challenges", and "consequences of gambling in Iran" were two identified themes in this study. Conclusions: Although betting on three sports are legal in Iran, various forms of illegal gambling are common.